Induction heating type cooktop and operating method thereof

Abstract

An induction cooktop includes an upper plate glass on which a cooking container is placed, a working coil generating a magnetic field to heat the cooking container, an inverter driven to flow a current through the working coil, an impedance calculation unit calculating the impedance of the cooking container on the basis of a parameter of the inverter, and an overheated state determination unit determining whether the cooking container is overheated, based on the impedance.

1 - 10 . (canceled) 
     
     
         11 . An induction cooktop, comprising:
 an upper plate glass configured to receive a cooking container;   a working coil configured to generate a magnetic field so as to heat the cooking container;   an inverter configured to be driven to allow current to flow through the working coil; and   a processor configured to:
 calculate an impedance of the cooking container based on a parameter of the inverter; and 
 determine whether the cooking container is in an overheated state based on the calculated impedance. 
   
     
     
         12 . The induction cooktop according to  claim 11 , wherein the processor is further configured to:
 calculate a slope of the impedance; and   determine the overheated state in response to the slope of the impedance being greater than a threshold slope.   
     
     
         13 . The induction cooktop according to  claim 12 , wherein the processor is further configured to determine the overheated state based on the slope of the impedance, in response to an operating time in a heating mode for heating the cooking container exceeding a first reference time. 
     
     
         14 . The induction cooktop according to  claim 11 , wherein the processor is further configured to:
 detect a material of the cooking container; and   determine the overheated state in response to the impedance of the cooking container being greater than a predetermined impedance corresponding to the detected material of the cooking container.   
     
     
         15 . The induction cooktop according to  claim 14 , further comprising non-transitory memory configured to store data in which an impedance for distinguishing an overheated state for each predetermined material of the cooking container is mapped. 
     
     
         16 . The induction cooktop according to  claim 14 , wherein the processor is further configured to determine the overheated state based on the impedance, in response to an operating time in a heating mode for heating the cooking container exceeding a second reference time. 
     
     
         17 . The induction cooktop according to  claim 11 , wherein the processor is further configured to:
 determine the overheated state based on a slope of the impedance, in response to an operating time in a heating mode for heating the cooking container exceeding a first reference time; and   determine the overheated state based on the impedance, in response to the operating time in the heating mode for heating the cooking container being less than the first reference time.   
     
     
         18 . The induction cooktop according to  claim 17 , wherein the processor is further configured to determine the overheated state based on the impedance, in response to the operating time in the heating mode for heating the cooking container being less than the first reference time and exceeding a second reference time, the second reference time being less than the first reference time. 
     
     
         19 . The induction cooktop according to  claim 11 , wherein the processor is further configured to:
 detect a material of the cooking container based on an impedance of the cooking container, immediately upon starting a heating mode for heating the cooking container; and   determine the overheated state using the impedance, in response to an operating time in the heating mode exceeding a second reference time.   
     
     
         20 . An operating method of an induction cooktop, the induction cooktop including an inverter, a working coil, and an upper plate, the operating method comprising:
 disposing a cooking container on the upper plate;   driving the inverter to allow current to flow through the working coil;   heating the cooking container by a magnetic field generated in the working coil;   calculating an impedance of the cooking container based on one or more parameters of the inverter while the cooking container is heated; and   determining whether the cooking container is in an overheated state based on the impedance.   
     
     
         21 . The operating method of  claim 20 , further comprising reducing the magnetic field generated in the working coil or turning off the cooktop, in response to determining the cooking container is in the overheated state. 
     
     
         22 . The operating method of  claim 21 , wherein the reducing the magnetic field generated in the working coil includes controlling heating of the cooking container to maintain a constant value. 
     
     
         23 . The operating method of  claim 21 , wherein the determining whether the cooking container is in the overheated state includes:
 calculating a slope of the impedance over time; and   determining the cooking container as being in the overheated state if the slope of the impedance is greater than a threshold slope.   
     
     
         24 . The operating method of  claim 23 , wherein the slope of the impedance is calculated only after a first reference time, and
 wherein the threshold slope is a value corresponding to a change from a boiling state to the overheated state.   
     
     
         25 . The operating method of  claim 24 , further comprising determining a material of the cooking container based on the impedance of the cooking container before the first reference time and after a second reference time, the second reference time being less than the first reference time. 
     
     
         26 . The operating method of  claim 20 , wherein the impedance of the cooking container is calculated after detecting the material of the cooking container, and
 wherein the method further comprises determining that the cooking container is in the overheated state in response to the calculated impedance being greater than a predetermined impedance corresponding to the detected material of the cooking container.   
     
     
         27 . The operating method of  claim 20 , further comprising:
 determining a material of the cooking container based on the impedance of the cooking container immediately upon starting the heating of the cooking container; and   controlling the heating of the cooking container based on the determined material to maintain the cooking container at a consistent temperature.   
     
     
         28 . An operating method of an induction cooktop, the induction cooktop including a working coil and an upper plate, the operating method comprising:
 disposing a cooking container on the upper plate;   heating the cooking container by applying current to the working coil;   determining whether the cooking container is in an overheated state based on one of an inductance or an impedance of the cooking container; and   stopping heating of the cooking container or reducing heating of the cooking container in response to determining that the cooking container is in an overheated state.   
     
     
         29 . The operating method of  claim 28 , wherein the determining whether the cooking container is in the overheated state includes:
 calculating a slope of the inductance over time; and   determining the cooking container as being in the overheated state if the inductance slope is greater than a threshold value.   
     
     
         30 . The operating method of  claim 28 , further comprising:
 determining a material of the cooking container based on the inductance of the cooking container immediately upon starting the heating of the cooking container; and   controlling the heating of the cooking container based on the determined material.